JP2022125739A - photoelectric sensor - Google Patents

Abstract

To provide a photoelectric sensor that enables a quantity of received light to be easily confirmed.SOLUTION: A photoelectric sensor 10 comprises a projector 11 projecting detection light LW, a light receiver 12 receiving the detection light LW, and a controller 20. The controller 20 includes: a detection unit 33 that detects presence/absence of a detection object W on the basis of a quantity of the detection light LW received by the light receiver 12 and outputs a detection signal K1; and a signal production unit 34 that, on the basis of the quantity of the detection light LW received by the light receiver 12, produces a received light quantity signal K2 of a pulse width in accordance with the quantity of the light and outputs the received light quantity signal K2.SELECTED DRAWING: Figure 3

Description

The present disclosure relates to photoelectric sensors.

Conventionally, a photoelectric sensor used for detecting an object has a sensor unit, and a light projecting section and a light receiving section connected to the sensor unit. The light projecting section and the light receiving section are arranged with an area through which an object passes therebetween. The sensor unit outputs a detection signal indicating the presence or absence of an object in a detection area between the light projecting section and the light receiving section based on the amount of light received by the light receiving section. The photoelectric sensor has a display that displays the amount of light received by the light receiving section (see, for example, Patent Document 1). In addition, in the above transmissive photoelectric sensor, a light projecting part and a light receiving part are integrally provided, and a reflection sensor that outputs a detection signal indicating the presence or absence of an object based on the amount of light reflected by the object is received. There is also a photoelectric sensor of the type.

JP 2013-076681 A

By the way, the amount of light received by the light-receiving part decreases due to the adhesion of dust and the like to the light-projecting part and the light-receiving part due to the influence of the surrounding environment. A decrease in the amount of received light causes an erroneous detection. For this reason, as in the photoelectric sensor described above, the amount of received light is confirmed by a display provided in the sensor unit, and processing such as removing dust or changing the threshold value for detecting the amount of received light is required. need to do. However, it may be necessary to go to the sensor unit to see it, or depending on the installation state of the sensor unit, the display may be installed in a place where it cannot be seen, making it difficult to check.

The photoelectric sensor of the present disclosure detects the presence or absence of a detection target based on the light intensity of the detection light received by the light-projecting unit that projects detection light, the light-receiving unit that receives the detection light, and the light-receiving unit. a detection unit for outputting a detection signal; and a signal generation unit for generating a light reception amount signal having a pulse width corresponding to the light amount based on the light amount of the detection light received by the light receiving unit and outputting the light reception amount signal. and provided.

The photoelectric sensor according to the present disclosure can easily confirm the amount of light received from the pulse width.

Schematic block diagram of a photoelectric sensor. Explanatory drawing of a controller. Block diagram of a photoelectric sensor. 4 is a flow chart showing the operation of the controller; Waveform diagram showing the operation of the controller. Waveform diagram showing the operation of the controller. The block diagram of the photoelectric sensor of the example of a change.

An embodiment will be described below with reference to FIGS. 1 to 6. FIG.
As shown in FIG. 1, the photoelectric sensor 10 detects the presence or absence of a detection target W. As shown in FIG. The detection target W is, for example, an object such as a circuit board, a resin molded product, or the like.

The photoelectric sensor 10 has a light projector 11 , a light receiver 12 and a controller 20 . The light projector 11 has a light projecting head 11a and a fiber cable 11b. The fiber cable 11b is connected to the controller 20. FIG. The controller 20 is configured such that the fiber cable 11b is detachable. The light receiver 12 has a light receiving head 12a and a fiber cable 12b. Fiber cable 12 b is connected to controller 20 . The controller 20 is configured such that the fiber cable 12b is detachable.

The controller 20 is connected to the processing device 100 . For example, processing device 100 has a general purpose I/O port and controller 20 is connected to the general purpose I/O port. The processing device 100 processes the object W to be detected. When the object W to be detected is a circuit board, the processing device 100 controls the transportation of the object W to be detected (circuit board), mounts electronic components and the like on the circuit board, and the like.

The light projecting head 11a and the light receiving head 12a are arranged so that the object W to be detected passes therebetween. For example, the light projecting head 11a and the light receiving head 12a are arranged across a transport path for transporting the object W to be detected. The light projecting head 11a and the light receiving head 12a are fixed so as to face each other. The light receiving head 12a receives the detection light LW emitted from the light projecting head 11a. The detection target W blocks at least part of the detection light LW traveling from the light projecting head 11a to the light receiving head 12a. The amount of the detection light LW in the light receiving head 12a, that is, the amount of light received changes (decreases) depending on the presence or absence of the object W to be detected. The controller 20 detects the presence or absence of the detection target W based on this change in the amount of light received. Then, the controller 20 outputs a detection signal K1 indicating the presence or absence of the object W to be detected.

The controller 20 inputs a predetermined external input signal CNX from the processing device 100 . The external input signal CNX is a signal (processing command) that the processing device 100 instructs the photoelectric sensor 10 to perform a predetermined process. The controller 20 executes processing based on the external input signal CNX.

Processing in the photoelectric sensor 10 includes, for example, detection processing, teaching processing, and incident light amount confirmation processing. The detection process performs normal detection operation and detection output. The teaching process performs saturation avoidance and limit teaching. The incident light amount confirmation process is for outputting the amount of received light.

In the normal detection operation and the detection output, as described above, the detection light LW is emitted from the light projecting head 11a toward the light receiving head 12a, and the presence or absence of the detection target W is detected based on the amount of light received by the light receiving head 12a. It outputs a detection signal K1. The saturation avoidance is to adjust the amount of light projected from the light projecting head 11a, that is, the light amount of the detection light LW so that the level of the light receiving signal DW in the light receiving circuit 23 is not saturated. Limit teaching is to set a threshold for determining the presence or absence of the object W to be detected. The received light amount of the detection light LW set by saturation avoidance is set as a reference level, and a value lower than the reference level by a predetermined value (shift amount) is set as a threshold value.

Teaching processing is performed, for example, when the distance between the light projecting head 11a and the light receiving head 12a (head-to-head distance) is changed. If the detection object W is small with respect to the distance between the heads, the change in the light amount of the detection light LW due to the detection object W, that is, the change in the amount of received light is small. In this case, the detection target W between the light projecting head 11a and the light receiving head 12a may not be detected, that is, erroneous detection may occur. Therefore, the head-to-head distance is adjusted according to the size of the object W to be detected, that is, the head-to-head distance is reduced. Then, the amount of incident light of the detection light LW on the light receiving head 12a increases, and the light receiving signal DW becomes saturated. Therefore, the projection amount of the detection light LW in the projection head 11a is adjusted.

As shown in FIG. 2, the controller 20 has an operation section 26 and a display section 27 . The operation unit 26 includes a plurality of switches 26a, 26b, 26c, 26d. The switch 26a is, for example, a switch for mode selection. Switches 26b to 26d are switches for changing set values. The controller 20 displays the incident light amount (received light amount) of the detection light LW in the light receiving head 12a, the set value (threshold value), and the like on the display unit 27 . Based on the amount of received light displayed on the display unit 27, it is possible to confirm the amount of incident light (amount of received light), adjust the positions of the light projecting head 11a and the light receiving head 12a, and the like.

As shown in FIG. 3, the controller 20 includes a control circuit 21, a light projecting circuit 22, a light receiving circuit 23, an input circuit 24, an output circuit 25, a display section 27, an operation section 26, and a terminal section .
The light projecting circuit 22 includes a light projecting element 22a. The light projecting circuit 22 drives the light projecting element 22a so as to emit light according to the light projecting signal CW. The driven light projecting element 22a emits light. The light emitted from the light projecting element 22a is sent to the light projecting head 11a via the fiber cable 11b. The projection head 11a includes a lens of a predetermined shape and emits strip-shaped light (detection light LW).

The light received by the light receiving head 12a is sent to the light receiving circuit 23 via the fiber cable 12b. The light receiving circuit 23 includes a light receiving element 23a. The light receiving element 23a photoelectrically converts the light transmitted through the fiber cable 12b to generate a voltage signal. The light receiving circuit 23 amplifies the voltage signal generated by the light receiving element 23a and outputs the amplified signal as the light receiving signal DW. The received light signal DW is an analog signal having a level (voltage) corresponding to the amount of light received by the light receiving head 12a and the amplification factor for amplifying the voltage signal. The light projecting head 11a, fiber cable 11b, and light projecting circuit 22 (light projecting element 22a) constitute a light projecting section, and the light receiving head 12a, fiber cable 12b, and light receiving circuit 23 (light receiving element 23a) constitute a light receiving section.

The terminal portion 28 includes four terminals 28a, 28b, 28c and 28d. The terminal portion 28 is configured as a connector for connecting signal lines, for example. The first terminal 28 a and the fourth terminal 28 d supply power to the controller 20 . The operating voltage VS is supplied to the first terminal 28a, and the fourth terminal 28d is the ground (GND). The operating voltage VS is supplied to the control circuit 21 , the light projecting circuit 22 , the light receiving circuit 23 , the output circuit 25 and the input circuit 24 . The second terminal 28b is an output terminal, and outputs the detection signal K1 and the received light amount signal K2 to the outside of the controller 20. FIG. The third terminal 28c is an input terminal, and the above-described external input signal CNX is supplied from the outside of the controller 20, the processing device 100 shown in FIG. The input circuit 24 is connected to the third terminal 28c. The input circuit 24 receives an external input signal CNX and outputs an external command signal CNI to the control circuit 21 according to the external input signal CNX. The external input signal CNX is a pulse signal, and the input circuit 24 outputs an external command signal CNI having a pulse width equal to the pulse width of the external input signal CNX. It is assumed that there is a signal input when the external command signal CNI (external input signal CNX) contains a pulse, and that there is no signal input when the pulse is not contained.

The control circuit 21 includes a control section 31 , a light projection control section 32 , a detection section 33 , a signal generation section 34 , a switching section 35 and an input signal determination section 36 . Note that the control circuit 21 can also be configured by an arithmetic processing device such as a CPU, for example.

The light projection control section 32 includes a storage section 32a. The amount of projected light is stored in the storage unit 32a. The amount of projected light is set by operating the operation unit 26 and teaching processing. The light projection control unit 32 outputs a light projection signal CW so that light corresponding to the amount of light to be projected is emitted from the light projection element 22a of the light projection circuit 22 .

The detector 33 receives the received light signal DW. The detection unit 33 includes a storage unit 33a. A threshold value for determination is stored in the storage unit 33a. This threshold value is set by operating the operation unit 26 and teaching processing. The detection unit 33 compares the level of the light receiving signal DW (light receiving level DL) with a threshold to detect the presence or absence of the detection target W. FIG. For example, the detection unit 33 includes an AD converter (analog-digital converter) and compares the level value of the received light signal DW with a threshold value. Then, the detection unit 33 outputs a detection signal K1 corresponding to the detection result. For example, as shown in FIG. 5, the detection unit 33 outputs a detection signal K1 of a first level (for example, H level) while detecting the detection target W, and does not detect the detection target W. Sometimes, it outputs a detection signal K1 of a second level (for example, L level) different from the first level.

The signal generator 34 receives the received light signal DW. The signal generator 34 generates a light receiving amount signal K2 having a pulse width corresponding to the level of the light receiving signal DW (light receiving level DL), and outputs the light receiving amount signal. For example, the signal generator 34 includes an AD converter and obtains the level value of the received light signal DW. Then, the signal generator 34 generates a received light amount signal K2 having a pulse width proportional to the level value. The signal generator 34 generates a light-receiving amount signal K2 having a pulse width of 1 ms as the basic unit of the level value. For example, when the level value is "3000", the pulse width of the received light amount signal K2 is 3000 ms.

A proportional coefficient may be set. The signal generation unit 34 has a storage unit 34a, and the proportional coefficient is stored in the storage unit 34a. The signal generator 34 calculates the pulse width based on the level value and the proportional coefficient. For example, the signal generator 34 uses the result of multiplying the level value by a proportional coefficient as the pulse width.

The input signal determination unit 36 measures the pulse width of the external command signal CNI. The input signal determination unit 36 determines a processing command from the processing device 100 shown in FIG. 1 based on the pulse width. The input signal determination unit 36 then outputs an internal control signal corresponding to the processing command. The external input signal CNX (external command signal CNI) is generated by the processing device 100 so as to have a pulse width that can be identified by the input signal determination section 36 . In this embodiment, the pulse width of the external input signal CNX (external command signal CNI) is set to the first width value or the second width value. For example, the first width value is set to 250ms and the second width value is set to 150ms. Note that the first width value and the second width value indicate standard pulse widths. Then, when the measured pulse width is within a predetermined range including the standard pulse width, the pulse width is determined to be the first width value or the second width value. The first width value and the second width value may be changed as appropriate.

For example, when the pulse width of the external command signal CNI (external input signal CNX) is the first width value, the external command signal CNI (external input signal CNX) indicates the received light amount output command. The input signal determination unit 36 outputs the first internal control signal CN1 when the pulse width of the external command signal CNI is the first width value. Also, when the pulse width of the external command signal CNI (external input signal CNX) is the second width value, the external command signal CNI (external input signal CNX) indicates a teaching process command. The input signal determination unit 36 outputs the second internal control signal CN2 when the pulse width of the external command signal CNI is the second width value.

Control unit 31 outputs first internal control signal CN<b>1 to switching unit 35 . Switching unit 35 switches between detecting unit 33 and signal generating unit 34 . Specifically, the switching unit 35 switches between a state in which the detection unit 33 outputs the detection signal K1 and a state in which the signal generation unit 34 outputs the received light amount signal K2.

Switching unit 35 switches the state in response to first internal control signal CN1.
Specifically, when the first internal control signal CN1 is not input, the switching section 35 causes the detection section 33 to output the detection signal K1. As a result, the photoelectric sensor 10 outputs a detection signal K<b>1 indicating the detection result of the detection target W from the second terminal 28 b of the terminal section 28 .

When the switching unit 35 receives the first internal control signal CN1, the switching unit 35 switches to a state in which the signal generating unit 34 outputs the received light amount signal K2. The signal generator 34 receives the first internal control signal CN1 and generates a received light amount signal K2 having a pulse width corresponding to the received light level DL at that time. After a predetermined time has passed since the first internal control signal CN1 was input, the signal generator 34 outputs a light receiving amount signal K2 having a pulse width corresponding to the light receiving level DL. The time from the input of the first internal control signal CN1 to the pulse of the received light amount signal K2 is taken as the third width value. A third width value is set to, for example, 250 ms. The third width value may be changed accordingly.

In other words, the photoelectric sensor 10 outputs the received light amount signal K2 having a pulse width corresponding to the received light level DL to the terminal portion 28 after the elapse of the third width value after the external input signal CNX indicating the received light amount output command is input. 2 output from the terminal 28b. Therefore, the processing device 100 shown in FIG. 1 outputs the external input signal CNX having a pulse width indicating the received light amount output command, and then outputs the pulse width of the signal that is input after the third width value. A received light level DL can be received.

Switching unit 35 switches to a state in which detecting unit 33 outputs detection signal K1 after a predetermined time has elapsed after switching to signal generating unit 34 . The time at this time is set to a time sufficient for the pulse of the received light amount signal K2 to be output to the outside. Specifically, it is set longer than the time corresponding to the maximum value of the light receiving level DL.

FIG. 4 shows the flow of processing in the control circuit 21. As shown in FIG.
In step S1, the control circuit 21 determines whether or not there is an external input signal CNX. When the control circuit 21 determines that there is no external input signal CNX (determination: NO), the control circuit 21 proceeds to step S2, performs normal detection operation and detection output, and outputs the detection signal K1.

When the control circuit 21 determines in step S1 that there is an external input signal CNX (determination: YES), the process proceeds to step S3 and executes pulse width measurement. The control circuit 21 measures the pulse width of the external input signal CNX, and proceeds to step S4.

In step S4, it is determined whether the pulse width is 150 ms (second width value). When determining that the pulse width is 150 ms (determination: YES), the control circuit 21 proceeds to step S5. In step S5, the control circuit 21 executes saturation avoidance and limit teaching processing.

If it is determined in step S4 that the pulse width is not 150 ms (determination: NO), the control circuit 21 proceeds to step S6. In step S6, the control circuit 21 determines whether the pulse width is 250 ms (second width value). If the pulse width is determined to be 250 ms (determination YES), the control circuit 21 proceeds to step S7. In step S7, the control circuit 21 executes a received light amount output process.

If it is determined in step S6 that the pulse width is not 250 ms (determination: NO), the control circuit 21 proceeds to step S8. In step S8, the control circuit 21 performs normal detection operation and detection output, and outputs the detection signal K1.

In FIG. 4, the process executed in step S8 is the same as the process executed in step S2. This suppresses malfunctions with respect to the external input signal CNX. The external input signal CNX is transmitted from the processing device 100 to the controller 20 of the photoelectric sensor 10 via the signal line WX, as shown in FIG. Depending on the state of the device that processes the detection target W detected by the photoelectric sensor 10, noise may be mixed in the signal transmitted through the signal line WX during the operation of the device, for example. The pulse width of pulses generated in the external input signal CNX by such noise is different from the first width value (250 ms) and the second width value (150 ms). Therefore, when different from the first width value and the second width value, normal detection operation and detection output are performed. As a result, the detection target W can be detected more reliably.

(Action)
Next, the operation of the photoelectric sensor 10 will be described.
FIG. 6 shows the external input signal CNX and the received light amount signal K2.

The control circuit 21 of the controller 20 shown in FIG. 3 measures the pulse width PW1 of the external input signal CNX. The control circuit 21 outputs the received light amount signal K2 when the pulse width PW1 is the first width value (250 ms). At this time, after the determination of the external input signal CNX, for example, after a predetermined time PW2 has elapsed from the pulse of the external input signal CNX, the received light amount signal K2 having a pulse width PW3 corresponding to the received light level is output. The processing device 100 shown in FIG. 1 measures the pulse width of the received light amount signal K2 and obtains the received light level in the photoelectric sensor 10 . That is, in the processing device 100, the light receiving level of the photoelectric sensor 10 can be confirmed from the pulse width of the light receiving amount signal K2. This saves the operator the trouble of checking the display unit 27 of the photoelectric sensor 10 . In addition, since it is not necessary to check the display section 27 of the controller 20, the degree of freedom in arranging the controller 20 is increased. Since the processing device 100 can check the light receiving level of the photoelectric sensor 10, the processing device 100 can determine the adhesion state of dust or the like on the light projecting head 11a and the light receiving head 12a based on the confirmed light receiving level, and notify the processing such as cleaning. can do.

As another means for confirming the amount of light received, analog communication using an analog output type controller and serial communication using a communication unit are available. However, these other means require a unit for communication, which causes problems such as an increase in equipment costs and a need for a large space for installation. In this respect, the photoelectric sensor 10 of the present embodiment detects the presence or absence of the detection target W and detects the presence of the detection target W by a simple configuration in which the controller 20 having the output circuit 25 is connected to the general-purpose I/O port of the processing device 100. Confirmation of quantity can be performed.

The control circuit 21 of the controller 20 measures the pulse width of the external input signal CNX, and when the pulse width is the second width value (150 ms), performs saturation processing and limit teaching processing. Therefore, when the positions of the light projecting head 11a and the light receiving head 12a are changed according to the object W to be detected, the amount of projected light and the threshold value can be easily set.

As described above, according to this embodiment, the following effects are obtained.
(1) The photoelectric sensor 10 includes a light projector 11 that projects the detection light LW, a light receiver 12 that receives the detection light LW, and a controller 20 . The controller 20 detects the presence or absence of the detection target W based on the light amount of the detection light LW received by the light receiver 12, and includes a detection unit 33 that outputs a detection signal K1, and the light amount of the detection light LW received by the light receiver 12. and a signal generation unit 34 that generates a light reception amount signal K2 having a pulse width corresponding to the light amount based on and outputs the light reception amount signal K2. With this configuration, the amount of light received by the light receiver 12 can be easily confirmed from the pulse width of the light amount signal K2.

(2) The output circuit 25 that outputs the detection signal K1 and the light reception amount signal K2 to the second terminal 28b, the state in which the detection unit 33 outputs the detection signal K1, and the signal generation unit 34 that outputs the light reception amount signal K2. and a switching unit 35 for switching between the output state and the output state. According to this configuration, the detection signal K1 and the received light amount signal K2 can be output from one second terminal 28b without changing the number of terminals. Further, it is possible to suppress the shape change due to the increase in the number of terminals and the size increase of the controller 20 .

(3) an input circuit 24 connected to a third terminal 28c for inputting an external input signal CNX via the third terminal 28c; and an input signal determination unit 36 that generates the first internal control signal when the input signal determination unit 36 generates the first internal control signal. The switching unit 35 switches to a state in which the signal generating unit 34 outputs the received light amount signal K2 in response to the first internal control signal, and the detecting unit 33 outputs the detection signal K1 after outputting the received light amount signal K2. switch to the state where According to this configuration, the outputs of the detection signal K1 and the received light amount signal K2 can be easily switched by the external input signal CNX having different pulse widths. By switching the state of outputting the detection signal K1 and the state of outputting the received light amount signal K2, it is possible to eliminate the need to determine whether the signal output to the outside is the detection signal K1 or the received light amount signal K2. , can easily receive both signals.

(4) The input signal determination section 36 generates the second internal control signal CN2 when the pulse width is the second width value. The controller 20 includes a control section 31 that performs teaching processing in response to the second internal control signal CN2. According to this configuration, for example, when the distance between the light projecting head 11a and the light receiving head 12a (head-to-head distance) is changed, it is possible to easily avoid saturation in the light receiving circuit 23 and set the threshold value. .

[Change example]
The description of the embodiment is an example of a form that the photoelectric sensor related to the present disclosure can take, and is not intended to limit the form. In addition to the embodiment, the present disclosure can take a form in which, for example, modifications of the embodiments shown below and at least two modifications not contradicting each other are combined.

- FIG. 7 shows a schematic block diagram of a modified photoelectric sensor 10a. The output circuit 25 of the photoelectric sensor 10 a includes a first output circuit 25 a connected to the detection section 33 and a second output circuit 25 b connected to the signal generation section 34 . By including the first output circuit 25a and the second output circuit 25b, a circuit configuration suitable for signal output can be achieved.

- In the photoelectric sensor 10a of the modification shown in FIG. 7, the switching unit 35 may switch between the first output circuit 25a and the second output circuit 25b.
- The photoelectric sensor 10a of the modified example shown in FIG. 7 may be configured to include a terminal connected to the first output circuit 25a and a terminal connected to the second output circuit 25b.

- The photoelectric sensors 10 and 10a may be configured to include a timer section. The timer section may be provided in the switching section 35 , provided separately from the switching section 35 , or provided in the control section 31 . The signal generator 34 may be put into a state in which the signal generating unit 34 outputs the received light amount signal at a set time by the timer unit. The set time can be appropriately set to several hours, 24 hours corresponding to one day, time corresponding to multiple days, and the like.

Further, the timer section may be set to a state in which the signal generating section 34 outputs the received light amount signal at a predetermined time as a set time. For example, the state may be switched according to the time when the processing apparatus 100 shown in FIG. 1 starts or ends the operation.

The photoelectric sensor may have a configuration in which the light projecting element 22a is mounted on the light projecting head 11a and the light receiving element 23a is mounted on the light receiving head 12a.
The switching section 35 may switch between the detecting section 33 and the signal generating section 34 based on the operation of the operating section 26 . For example, when a plurality of photoelectric sensors are connected to the processing device 100 shown in FIG. 1, the processing device 100 obtains the light receiving level DL by operating the operation unit 26, and the operated photoelectric sensor needs to be cleaned or otherwise treated. It can be easily determined whether

In contrast to the above embodiment, the light projecting head 11a and the light receiving head 12a are integrated as a light projecting/receiving head. It may be a sensor. Further, the photoelectric sensor may have a configuration in which the light projecting element 22a and the light receiving element 23a are mounted on the light projecting and receiving head. A photoelectric sensor in which a light projecting/receiving head and a controller are integrated may be used.

Reference Signs List 10, 10a photoelectric sensor 11 light projector 11a light projecting head 11b fiber cable 12 light receiver 12a light receiving head 12b fiber cable 20 controller 21 control circuit 22 light projecting circuit 22a light projecting element 23 light receiving circuit 23a light receiving element 24 input circuit 25 output circuit 25a 1 output circuit 25b second output circuit 26 operation unit 27 display unit 28 terminal unit 28a first terminal 28b second terminal 28c third terminal 28d fourth terminal 31 control unit 32 light projection control unit 32a storage unit 33 detection unit 33a storage unit 34 signal generation unit 34a storage unit 35 switching unit 36 input signal determination unit 100 processing device CN1 first internal control signal CN2 second internal control signal CNI external command signal CNX external input signal CW light projection signal DL light reception level DW light reception signal K1 detection Signal K2 Received light amount signal LW Detected light PW1 Pulse width PW2 Predetermined time PW3 Pulse width S1 to S8 Step VS Operating voltage W Object to be detected WX Signal line

Claims (8)

a light projecting unit that projects the detection light;
a light receiving unit that receives the detection light;
a detection unit that detects the presence or absence of a detection target based on the amount of the detection light received by the light receiving unit and outputs a detection signal;
a signal generation unit that generates a light reception amount signal having a pulse width corresponding to the light amount based on the light amount of the detection light received by the light receiving unit and outputs the light reception amount signal;
Photoelectric sensor with an output circuit that outputs the detection signal and the received light amount signal to an output terminal;
a switching unit for switching between a state in which the detection unit outputs the detection signal and a state in which the signal generation unit outputs the received light amount signal;
The photoelectric sensor of claim 1, comprising: an input circuit connected to an input terminal for inputting an external input signal through the input terminal;
an input signal determination unit that measures the pulse width of the external input signal and generates a first internal control signal when the pulse width is a first width value;
with
The switching section switches to a state in which the signal generating section outputs the received light amount signal in response to the first internal control signal, and the detecting section outputs the detection signal after outputting the received light amount signal. switch to the state of
The photoelectric sensor according to claim 2. The switching unit switches to a state in which the signal generating unit outputs the received light amount signal according to a set time, and switches to a state in which the detecting unit outputs the detection signal after outputting the received light amount signal.
The photoelectric sensor according to claim 2. The switching unit switches to a state in which the signal generating unit outputs the received light amount signal based on the operation of the operating unit, and the detecting unit outputs the detection signal after outputting the received light amount signal. switch to the state
The photoelectric sensor according to claim 2. an input circuit connected to an input terminal for inputting an external input signal through the input terminal;
an input signal determination unit that measures the pulse width of the external input signal and generates a first internal control signal when the pulse width is a first width value;
with
The switching unit switches to a state in which the signal generating unit outputs the received light amount signal in response to the first internal control signal.
The photoelectric sensor according to claim 4 or 5. The input signal determination unit generates a second internal control signal when the pulse width has a second width value,
A control unit that performs teaching processing in response to the second internal control signal,
The photoelectric sensor according to claim 3 or 6. The output circuit is
a first output circuit that outputs the detection signal to the output terminal;
a second output circuit that outputs the received light amount signal to the output terminal;
A photoelectric sensor according to any one of claims 2 to 7, comprising:

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